Stoker mechanism



Dec. 2, 1924. 1,517,773

- w. G. DIMAN ET AL STOKER MECHANISM I Filed March 16, 1921 5 Sheets-Sheet 1 9 mam Walter G'flz'mafi. y Jbim M Keuw/ Dec. 2, 1924. 1,517,773

1 w. G. DIMAN ET AL STOKER MECHANISM Filed March 16, 1921 5 Sheets-Sheet 2 III II I=IIIIIIIW Dec. 2, 1924. 1,517,773 I W. G. DlMAN ET AL STOKER MECHANISM Filed March 16, 1921 3 Sheets-Sheet S WALTER G. DURAN AND JOHN M. KENDALL, @15 HIANCHESTEE, NEW HAMPSHRE.

STUKEIQI MECHANJEQ M.

To all whom it may concern;

Be it known that we, WALTER G. DIMAN and Jon M. KENDALL, both citizens of the United States of America, and residents of l /lanchester, in the county of Hillsborough of mechanical stokers it is desirable for eflicient operation to avoid the feeding of lumps of fuel above a predetermined size and it is therefore common to pass the fuel through a suitable crushing ,4 mechanism whereby to reduce the size of lumps which may be larger than the permissible maximum. The usual practice is to remove the coal from the cars or receiving bins, pas it through a crusher and then to stor'edt in a second bin preparatory to dumping it as needed into the hopper or other receiving element of the stoking apparatus. Such a procedure however is manifestl undesirable, not only from the standpoint of the cost entailed in the relatively large number of handlings required, but also in many cases by reason of the additional space consumed by the secondary bin, while the added fire risk incident to the storage of finely divided fuel is also an element which must be chnsidered in carrying out the operation as described. Moreover, when stored in a secondary hin, there is more or less tendency for the larger particles of the fuel to become segregated from the finer ones with resultant possibility of choking of the stoker mechanism and lack of uniformity of re-' sults when the fuel is fired.

The principal object of the present invention is to provide for overcoming, in lar e measure, the undesirable features usual y incident to the operation of automatic stokers as above outlined, and to this end it is proposed to provide coal crushing means so related to the stoking mechanism as to crush the fuel and present it directly to the stoking mechanism in consonance with the demands of the latter. The present inven-- tion is broadly applicable to mechanical stokers in general, and various arrangements might well be employed for automatically Application filed March Ml, 15921. serial No. d5a,'?4l5.

controlling the operation of the crusher device in accordance with requirements of the stoker mechanism. In fact, if desired, the crushers for a series of stokers might be driven from a common source of power, the application of the drive to each individual crusherbeing however under the direct control of its corresponding stoker.

' A preferred arrangement, however, and that Which is herein specifically disclosed, contemplates the mounting of a crusher de vice directly upon a stoker of that type employing a reciprocating ram for feeding the fue into the furnace. With this arrangement the crushed fuel may be delivered directly in front of the ram thus eliminating one or more of the usual handlings as well as dispensing with the secondary storage bin. For actuating the crusher device, advantage may be taken of the fact that the backward stroke of the ram is normally idle, and by suitably connecting the ram and crusher, the ram, on its rearward stroke may be caused to actuate the crusher device. By employing an intermittent drive such as a pawl and ratchet between the ram and the crusher the latter may remain idle during the forward or feeding stroke of the ram, thus avoiding the delivery of fuel to the stoker at an improper time, while also to a. large extent equalizing the power consumed on the forward and rearward stokes of the ram. The crusher preferablv comprises toothed rolls arranged in the lower portion of a hopper. whose outlet is dirertlv above the path of the stoker ram, the rolls being of such character and the teeth thereon being so arran cd as to reduce the coal to the desired size or feeding to the furnace.

The crusher rolls in the hopper also serve as fuel delivering and agitating means whereby there is eliminated the possibility of the choking of the hopper delivery opening by the brid ing of the fuel therein, While by the emp oyment of rolls of proper proportions the maximum size of the fuel particles may be fixed as desired.

A preferred arrangement of parts whereby the object of the invention may be attained is illustrated by way of example in the accompanying drawings wherein Figure 1 is a side elevation illustrating the various features of the present invention as, applied to a stoker of well known ty' Fig. 2 is a plan view of the device siown in Fig. 1;'

Fig. 3 is an end elevation of the mechanism seen in Fig. 1, portions thereof being omitted for the sake of clearness of illustration Fig. 4; is a vertical cross section on the line 4-1 of Fig. 1;

Fig. 5 is a detail cross section on the line 55 of Fig. 3 illustrating a form of intermittent drive employed;

Figs. 6 and 7 are side and end elevations respectively of a gear forming a portion of the intermittent drive; and

Figs. 8, 9 and 10 are views corresponding respectively to Figs. 1,2 and 3 but illustrating a modified form of the apparatus.

Referring to Figs. 1 to 7 inclusive, the features forming the present invention are illustrated as applied to an under feed stoker of well known commercial form and having the general characteristics of that illustrated in the patent to Daley, No. 733,374, July 14, 1903. As illustrated, the front wall of the boiler setting is indicated in broken lines at 1, such wall having a feed opening 2 with which is aligned a grate or retort 3 upon which the bed of fuel 1 is burned. The stoker mechanism comprises broadly a substantially cylindrical guide structure comprising the lower member 6 and the upper member 7 secured together by means of lateral flanges and having end flan es 5 whereby they are attached to the boiler setting. This cylindrical guide casing forms a fuel receiving chamber havin an immovable floor and extends substantially, horizontally outwardly from the boiler setti and is provided at its outer extremity with a flange 5, to which is secured the end flange of a steam cylinder 8. This cylinder may be supported if desired, upon a column or standard 8 and is provided with a piston 'havin a piston rod 9. The piston rod 9 exten s axially of the guide casin comprising the members 6 and 7 and as secured thereto and slidable within such casing a substantially cylindrical ram 10. This ram is preferably hollow and connected to the piston rod 9 by means'of a suitable nut or other fastening means 11. The lower part of the member 6 is longitudinally slotted at its outer portion for the reception of a guide fin 12 which projects downwardly from and is fixedly secured to the ram 10.

As thus constructed the stoker device is substantially like those commonly employed and wherein, upon admission of steam to the steam cylinder, the ram is caused to travel along the cylindrical guide pushing any fuel which may have been'deposited in front of the same through the opening 2 and into the furnace chamber.

In accordance with the present invention there is secured to the lower portion of the fin 12 a plate 13, such plate being held in place as by means of bolts 14. Projecting outwardl from the plate 13 and substantially at rig t angles to the fin 12 is a bar 15 whose outer extremity is connected integral- 1y or otherwise to a carriage 16, such carriage being mounted upon rollers or wheels 17 suitably guided by a rail 18. v The plate 13 is provided near its rear end with a second outstanding arm or bar 19, such arm bein arranged to diverge from the arm 15 and eing connected to the carriage 16 near the rear portion of the latter. The carriage 16 is thus rigidly secured to the fin 12 and is constrained to partake of the movements of the ram.

The rear portion of the casing member 7 is provided with an opening 20 at its upper side, such opening being defined by a pair of oppositely diverging flange members 21. Resting upon the flange members 21 is a substantially rectangular box-like casing 22 having a flange 23 at its lower portion whereby such box or casing may be secured to the flange members 21 as by means of bolts 24. The box-like member 22 is also provided with a flange 25 at its upper edge to which is secured a flange projecting from the lower portion of a hopper 27.

J ournalled in the lateral walls of the boxlike member 22 are the parallel shafts 28, 29,

such shafts serving to support within the receptacle 22 a pair of crushing rolls 30, 31, respectively. These rolls are provided with outstanding teeth such as 32, 32, the latter being longer if desired than the former, it being understood however, that the exact arrangement of the crushing teeth is not essential to the present invention, it being contemplated that any suitable and efiicient form of crushing rolls may be employed. Fixed to the respective shafts 28, 29 are a pair of intermeshing pinions 33, 33, wherelllU by the rolls 30, 31 are constrained to rotate in opposite directions.

Secured to the side of the guide casing comprising the members 6 and 7 is a plate 34, such plate having extending upwardly and outwardly therefrom a. bracket incur ber upon which is rotatably supported a gear wheel 36, such gear wheel meshing with the pinion 33. The members 6, 7 of the guide casing are provided with outstanding bosses 38, 39, respectively, and secured to the outer surface of said bosses is a plate 40, such plate being retained in proper position as by means of bolts 41. Projecting laterally outward from the plate 40 is a shaft 42 which may, if desired, be formed integrally with the plate. Upon the shaft 42 are free- 1y mounted a pair of gears 43, 44 respec tively, the latter gear meshing with the gear 36 and serving to drive the latter.

The gear 43 (see Fig. 5) is provided with an annular groove 46 in its outer face, such groove being provided in its outer peri heral wall with one or more recesses 47. W ithin naiawa the recesses 47 are arranged pawl members 48 pivotally secured therein by means of pins such as 49. I

Projecting from the gear 44 is an annular flange or boss having formed on its peripheral surface a series of ratchet teeth 51, such flange 50 with its ratchet teeth being operatively positioned within the roove 46 in the gear 43. As thus arranged t e awls 48 are adapted to coperate with the teet 51 for imparting movement to the gear 44 upon movement of the gear 43 in one direction but permit the gear 44 to remain at rest upon reverse rotation of the gear 43. The gear 43 meshes with a rack 45 mounted upon the carriage 10 and formed integral therewith if desired. 7

In the modified arrangement illustrated in Figs. 8, 9-and 10, the boiler setting 1, grate 3 and fuel bed 4 are illustrated asin the preceding figures. The cylindrical gu de casing for the ram 10 with the steam cylinder therefor and the guide fin 12 projecting from the ram are also like those previously described. The fuel crushing rolls .30, 31 and the supply hopper 27 all mounted upon the flanges 21 are also similar to those previously illustrated and described.

In the modified arrangement however, the plate 13 secured to the fin 12 is provided with an outwardly and upwardly directed arm 15" and with a second outwardly, up-

wardly and rearwardly extending arm 19*,

such arms being integrally united or otherwise secured if desired, to a carriage member 100. Projecting outwardly from the car'- riage member 100 are brackets 101 from the lower surface of which depend spaced In S 102 having journaled therebetween whee s or rollers 103. 104 is an elevated track for supporting and guiding the rolls 103, such track being mounted upon posts or standards 105. The crushing rolls 30, 31 are mounted upon parallel shafts 28, 29 respectively, provided with inter-meshing pinions '33", 33 respectively. The pinion 33" is substantially similar in construction to the gear 44 previously described being provided with an annular boss having peripherally disposed ratchet teeth. Loosely mounted upon the shaft 28 is a pinion 43 substantially similar construction to the pinion 43 previously described being provided with an annular recess for the reception of the boss projecting from the gear 33 and having one or more pawls for engaging the ratchet teeth of the latter. Mounted upon the carriage 100 is a rack member 45 whose teeth mesh with the gear 43 whereby to rotate the latter.

means of a manually operated valve or by automatic mechanism controlled by the steam pressure in the boiler or in other d0- siied manner. If it be assumed that a certain quantity. of fuel has passed down between the crusher rolls 30, 31 and into the lower portion of the guide casing, forward movement of the ram 10 will serve to push such fuel through the feed opening 2 and into the furnace. During the forward movement of the ram the rack carriage 16 is moved forwardly therewith thus rotating the gear 43. The arrangement of the pawls 48 is such however, that upon surh movement of the gear the pawls slip freely over the teeth 51 and thusno movement is im parted to the gear 44 or to the crusher rolls 30, 31. Upon completion of the feeding movement of the ram, steam is admitted to the other end of the cylinder 8, thus retracting the ram 10. As the rack carriage 16 begins to move rearwardly the pawls 48 engage ratchet teeth 51 of the gear 44, thus positively rotating the latter and thereby causing the rolls 30, 31 to rotate inwardly and downwardly toward each other. Such rotation of the rolls serves not only to crush any large lumps of coal which may be engaged by the teeth 32, 32, but also acts in a positive manner tofeed fuel down from within the receptacle 32 and to so agitate fuel in the lower portion of the hopper as to prevent any possibility of the bridging of the latter therein with consequent failure to properly feed fuel. Thus as the ram is retracted fuel is caused to fall into the lower ortion 6 of the guide casing, passing through the opening 20, the fuel thus being properly positioned for engagement by the ram upon its next forward stroke.

By this arrangement fuel is crushed and fed to the Stoker mechanism in exact accordance with the requirements of the latter, it being clear that if the stoker ram is slowed down by the automatic controlling mechanism usually employed, the feed of fuel thereto will .be correspondingly delayed. while if the stoke r mechanism is speeded up. the delivery of fuel thereto and the crushing .of such fuel will be correspondingly augmented.

The operation of the device illustrated in Figs. 8, 9 and 10 is substantially similar to that above described the only substantial difference being that in the modified form the intermediate driving gears have been dis ensed with.

; aving thus described the invention in a preferred embodiment of the same toget er with the mode of operation thereof, what we claim and desire to secure by Letters Patent of the United States is:

1. A stoker mechanism comprising a fuel hopper, reciprocatory fuel feeding means ad acent said hopper, and means responsive to-movement of said feeding means in one direction for discharging fuel from said hopper to said feeding means, said last named means being inoperativeon reverse movement of said feeding means.

2."In stoking mechanism including a fuel feedingdevice and crushing rollers for. supplying the fuel thereto, means for applying power. to the feeding device, and operative connections between the feeding device and the rolls for intermittently actuating the latter.

3. A stokcr mechanism havin a reciprocatory fuel feeding ram, a fue receptacle nance with the idle stroke of the ram.

5. In stoking mechanism the combination with a reciprocable feed ram of means forreciprocating said ram, feed rolls for intermittently supplying fuel to the ram, and direct connections between the ram and the rolls for transmitting power from the ram to the rolls on the idling stroke of the ram.

6. In a stokcr mechanism in combination,- a reciprocatory feed ram, a rack bar, a carriage for supporting said rack bar, and rigid connections between said ram and carriage whereby to reciprocate the rack bar in time with the movement of the ram, and means actuated by said rack bar for depositing fuel before said ram.

7. In a device of the class described, a reciprocatory feeding ram having an outstanding uide fin, a rack bar, a carria e therefor provided with a roller, a fixed guide rail for the roller and connections between said uide fin and carriage whereby to move the atter in 'consonance with the movement of the ram, and means actuated by said rack bar for depositing fuel before said ram.

8. .A stokcr mechanism having-a reciprocatory ram, a fue crushing roll, a drive pinion-fast to said roll, a rack bar reciprocable with the ram, a pawl-and-ratchet means interposed between Said rack bar and said pinion whereby to impart rotational movement to said pinion upon movement of said rack bar in one direction only.

9. In a stokcr mechanism, a reciprocatory fuel feeding element, a hopper arranged adj acent the ath of movement of said element, a roll within said hopper for controlling the delivery of fuel to said element, and drive means interposed between said roll and feeding element com rising a pinion having a pawl thereon an a second pinion having a ratchet tooth for engagement by said pawl whereby said roll is rotated to deliver fuel to said element only during the idle stokcr of the latter.

10. In a stokcr mechanism, areciproca tory fuel feeding element, a hopper arranged adjacent the path of movement of said element, a fuel crushing roll within said hopper for controlling the deliver of fuel to said element, and drive means or transmittin movement from said feeding element to se r roll, said means comprising a pinion having an annular cavity, pawls pivoted upon said pinion and projectin into said cavity, a second inion dispose coaxially with said first pinion, a substantially cylindrical boss pro ecting from said latter pinion within the cavity of said first pinion, and ratchet teeth on the peripheral surface of said boss for engagement with said pawls, said drivin means being arranged to rotate said roll on y during the idle stroke of said element.

11. In stoking mechanism the combination with .a fuel feeding member of means for supplying the fuel thereto, said supply means being intermittently o erated by the feed mechanism between fue ejecting movements thereof.

12. A stokcr mechanism com rising a feeding ram, a guide cylinder t erefor, a hop er'mounted upon said cylinder, a rotata 1e roll within said hopper, a shaft, a pair of ars mounted on said shaft, pawland-ratcfizt connections between said am, drive means interposed between, one 0 said gears and said roll, a rack engaging the other of said gears, and means for imparting movement to said rack in time with the actuation of the feed ram.

13. A fuel feeding mechanism comprising a reciprocable ram, a hopper arranged above the path of movement of the ram, a pair of cooperating crushing rolls, shafts for said rolls journaled in sald hopper, intermeshin pinions carried by said shafts, one of said pinions having a toothed boss projecting therefrom, a gear loosely mounted upon the shaft carrying said latter pinion and rovided with a awl for engaging the teat of said boss, and a rack member engaging said gear and having fixed connection to the ram.

Si ned b us at Manchester, N. H., this 9th ay of arch, 1921.

WALTER G. DIMAN. JOHN M. KENDALL. 

